[PATCH] fix aliasing for chars in global structures - take II

[Joseph S. Myers]

On Fri, 22 Mar 2002, Dan Nicolaescu wrote:

> Do you have any suggestion on how should I go about that? 
> I am not familiar at all with the standard process. 
> What I am thinking about is posting a question on comp.std.c and see
> if I can get a good reply. Is that a good first step? 

A good first step is reading the whole of the standard (including TC1 -
ISO or IEC will send the official PDF of TC1 free of charge, if it isn't
yet available for download).  Then all the C99 DRs, then all the C90 DRs.  
(These are linked to from readings.html.  Many C90 DRs are relevant to
C99, and show issues that have been found unclear in the past.)  The WG14
site has papers on various issues downloadable, a few of which might be
relevant (as might anything about relevant DRs in meeting minutes).

Norrish's thesis, also linked to from readings.html, is also worthwhile
reading for anyone interested in subtleties of the standard, how you
interpret it, and how you formally model it - even though it only deals
with a subset of C90, has some errors (or choices of interpretation
differing from those widely used), and doesn't seem to address these
aliasing issues.

Pay particular attention to the concept of "effective type".  It is new to
C99, and the exact interpretation of it is so far unclear.  Pay attention
also to the concept of "object" - again, asking Nick Maclaren for a copy
of his "What is an object?" paper would be worthwhile.

-- 
Joseph S. Myers
jsm28@cam.ac.uk